Multiple media outlets declared the Vermont senator the winner on Saturday evening after he won a plurality of delegates. By Sunday night, Sanders had 47.1 percent of delegate equivalents at 6,120 with 87 percent of precincts reporting.

"In Nevada, we have just put together a multigenerational, multiracial coalition, which is not only going to win in Nevada, it's going to sweep this country," Sanders said to a victory celebration in San Antonio, Texas.

President Donald Trump congratulated Sanders on his win Sunday before departing the White House for a trip to India.

"I think it was a great win for Bernie Sanders," he said. "We'll see how it all turns out. They've got a lot of winning to do."

Buttigieg's campaign late Saturday night sent a letter to the Nevada State Democratic party asking it to provide early vote and in-person vote totals by precinct, correct any errors identified by campaigns during the early voting and the second alignment and explain other anomalies in the data before releasing final caucus results.

The letter alleges that the process of integrating early votes into the results of the in-person caucuses "was plagued with errors and inconsistencies," stating that Buttigieg's campaign received more than 200 incident reports from precincts throughout the state.

The allegations from Buttigieg's campaign come after issues in the Iowa caucuses related to an app used to report the results. A recanvass of 81 precincts showed that Buttigieg's lead in state delegates over Sanders had fallen to .08 percent as the former mayor of South Bend, Ind., received 26.186 percent and the Vermont senator received 26.182.

Former New York Gov. Michael Bloomberg was not on the ballot in Nevada nor will he appear on the ballot in South Carolina, as his campaign has said they will forgo the first four primaries and appear on ballets in 14 states for Super Tuesday on March 3.

Sanders leads all candidates heading into the South Carolina primary on Saturday with 34 national convention delegates followed by Buttigieg at 23 with Warren, Klobuchar and Biden further behind.

Biden sought to encourage his supporters in Las Vegas after the Nevada caucus, calling out Sanders' status as a self-described Democratic socialist.

"We're alive, we're coming back and we're going to win," Biden said. "I ain't a socialist. I ain't a plutocrat. I'm a Democrat -- and I'm proud of it."

The Democratic candidates will seek to make their case to voters in a debate in South Carolina on Tuesday, with Steyer rejoining the field of Sanders, Buttigieg, Biden, Warren, Klobuchar and Bloomberg.

Steyer hit the polling requirements for the debate based on the results of a CBS News/YouGov poll in South Carolina released Sunday morning after failing to satisfy the polling requirements for the Nevada debate in which the Democratic National Convention removed fundraising goals, allowing Bloomberg to participate for the first time. Biden leads that poll with 28 percent followed by Sanders with 23 percent.